The 454 is a very large revolver (concealable only in winter under a thick coat). The mere size of it - 8 3/4" barrel, not to mention the rest of the gun -makes it intimidating. No, I don't necessarily think someone would realize it was a 454 per se, but they would know that they wouldn't be on the recieving end of it.
As far as penetration goes, I think that is why he uses hollow points.